The First Americans

At the height of the Ice Age, between 34,000 and 30,000
B.C., much of the world's water was locked up in vast
continental ice sheets. As a result, the Bering Sea was
hundreds of meters below its current level, and a land
bridge, known as Beringia, emerged between Asia
and North America. At its peak, Beringia is thought to have
been some 1,500 kilometers wide. A moist and treeless
tundra, it was covered with grasses and plant life,
attracting the large animals that early humans hunted for
their survival.

The first people to reach North America almost certainly
did so without knowing they had crossed into a new
continent. They would have been following game, as their
ancestors had for thousands of years, along the Siberian
coast and then across the land bridge.

Once in Alaska, it would take these first North Americans
thousands of years more to work their way through the
openings in great glaciers south to what is now the United
States. Evidence of early life in North America continues
to be found. Little of it, however, can be reliably dated
before 12,000 B.C.; a recent discovery of a hunting lookout
in northern Alaska, for example, may date from almost that
time. So too may the finely crafted spear points and items
found near Clovis, New Mexico.

Similar artifacts have been found at sites throughout North
and South America, indicating that life was probably
already well established in much of the Western Hemisphere
by some time prior to 10,000 B.C. Around that time the mammoth began to die out and the bison took its place as a principal source of
food and hides for these early North Americans. Over time,
as more and more species of large game vanished whether
from overhunting or natural causes plants, berries, and
seeds became an increasingly important part of the early
American diet. Gradually, foraging and the first attempts
at primitive agriculture appeared. Native Americans in what
is now central Mexico led the way, cultivating corn,
squash, and beans, perhaps as early as 8,000 B.C. Slowly,
this knowledge spread northward.

By 3,000 B.C., a primitive type of corn was being grown in
the river valleys of New Mexico and Arizona. Then the first
signs of irrigation began to appear, and, by 300 B.C.,
signs of early village life.

By the first centuries A.D., the Hohokam were
living in settlements near what is now Phoenix, Arizona,
where they built ball courts and pyramid like mounds
reminiscent of those found in Mexico, as well as a canal
and irrigation system.